Non-symmetric, partially fluorinated lubricant additives

ABSTRACT

Novel non-symmetric, partially fluorinated compositions and method of manufacture which are useful as lubricants or as additives to lubricant formulations involving the molecular structure: 
     
       
         R 1f —F′—R 2 —F″—R 3h   
       
     
     where R 1f  represents a wholly or partially fluorinated organic residue end group, F′ and F″ represent functional linkages which may be alike or different, R 2  represents the backbone and R 3h  represents a non-fluorinated organic residue end group. Such compositions are produced by reacting a mixture of alcohols, mercaptans or amines containing at least one partially fluorinated compound and at least one non-fluorinated compound in the mixture, thus producing the R 1f  and the R 3h  residues, with a difunctional organic compound (e.g., diacid, dinitrile, disulfonyl halide, diisocyanate, diisothiocyanate, diphosphoryl halide or dithiophosphoryl halide).

CROSS-REFERENCE TO RELATED APPLICATIONS

Applicants claim the benefit of Provisional Application 60/083,115 filedApr. 27, 1998 and Non-Provisional Application 09/299,251 filed Apr. 26,1999 now allowed.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

“Not Applicable”

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to lubricants. In particular, it describesnon-symmetric, partially fluorinated lubricants and additives, which aresoluble in lubricating oils and impart anti-wear and friction-reducingbenefits to lubricant formulations.

2. Description of the Prior Art

Two of the most important functions of a lubricant are to reducefriction and to reduce wear on moving parts. Full-film lubrication,where moving parts are always separated by a film of lubricant such thatthe parts never make contact, is an ideal that cannot always be achievedin practice. Design constraints, together with high load, slow speed,lubricant starvation, or low viscosity of the lubricant, may precludefull-film lubrication and increase the severity of contact. Theseconditions are often unavoidable during normal operation of machinery,and particularly severe during startup and shutdown.

In cases where full-film lubrication cannot be ensured at all times,anti-wear agents and friction modifiers are usually employed to modifythe surfaces to be lubricated. Such anti-wear agents modify thesesurfaces through adsorption or chemical reaction to form a new surfacethat can reduce friction and resist wear. Many kinds of anti-wear agentsare known. Some of the most widely used and relied upon are the zincdialkyldithiophosphates (ZDDPs), which find application in manydifferent types of lubricants. Although these compounds have been usedfor many years in passenger car motor oil, their use is currentlyrestricted (0.1% P vs. 0.12% allowed in the previous GF-1 specification)because the phosphorus from ZDDP poisons catalytic converters, leadingto increased emissions. It is anticipated that the future use of ZDDPmay be reduced even more than the current level. Anti-wear agents, whichcan be used in place of ZDDP or in addition to it, are therefore ofgreat interest.

Use of fluorinated and partly-fluorinated materials, as lubricants areknown. One limitation of the fluorinated and partly-fluorinatedmaterials previously known is their very low solubility in conventionallubricant base fluids such as natural and synthetic hydrocarbons andesters. Although solid additives may be used in lubricants, they poseseveral problems. For example, it is known that solidpolytetrafluoroethylene (PTFE) can be dispersed in lubricant fluids toreduce friction and wear. However, effectiveness of such a dispersedlubricant depends on maintaining the solid PTFE particles in stabledispersion. Achieving an indefinitely stable dispersion is a challenge,particularly in a formulated lubricant, which may contain detergents,dispersants, or surfactants that may destabilize the PTFE dispersion.Particles of a dispersed solid may flocculate over time in use. Suchflocculated particle may then plug or restrict flow of the lubricant inthe equipment and result in lubricant starvation in critical locations.The use of soluble additives instead of dispersed solid additiveseliminates this problem.

Unfortunately, in the case of PTFE, there is no equivalent material thatis soluble in common mineral oil base fluid. Other fluorinated materialshave been developed as lubricants, including some liquid highlyfluorinated materials such as perfluoropolyethers, but even these liquidhighly-fluorinated materials are insoluble in common mineral oil basefluids.

Finally, highly fluorinated materials are significantly more expensivethan common lubricant base fluids, making it impractical to use highlyfluorinated materials themselves as base fluids except in certainspecialized uses where lower cost base fluids are not acceptable.

In the prior art, the terms “partly-fluorinated” and “partiallyfluorinated” can be confusing since they may be used interchangeably, oreither one or both terms may used to refer generically to many differenttypes of organic compounds having some but not all of the hydrogenreplaced by fluorine substituents. Thus the terms as used in the priorart do not necessarily adequately describe the structure of the moleculein regard to placement of the fluorine substituents.

As used herein the term partly-fluorinated means that both end groups ofa molecule are fluorinated to some extent. Partly-fluorinated materials,particularly esters and ethers, have been disclosed as lubricants formagnetic media, for example, Japanese Patent 259482, Japanese Patent08259501, and U.S. Pat. Nos. 5,578,387; 5,391,814 and 5,510,513.

Japanese Patent 01122026 teaches use of fluorine containing dibasic acidesters derived from diacids up to C₈ as lubricants for magnetic media.This publication, as does PCT publication, US/92/08331, teaches that theacid structure from which the diester is formed may have double bondspresent. The molecular structures taught by each of these publicationsmay also have fluorine atoms present in each of the end group.

Partly-fluorinated adipic acid diesters,R_(f)(CH₂)_(x)O₂C(CH₂)₄CO₂(CH₂)_(x)R_(f), have been disclosed aslubricating coatings by Russian patent SU 449925. Bowers et al (Lubr.Eng., July-August, 1956, pages 245-253) studied the boundary lubricatingproperties of several similar esters. The compounds disclosed in thispublication have fluorine present in each of the diester groups that isthe fluorination is symmetric. These partly-fluorinated esters have verylow solubility in conventional lubricant base fluids and are therefore,of limited utility as additives in such base fluids.

Japanese Patent 2604186 discloses 1,2,3,4-butane-tetracarboxylic acidtetraesters with partly-fluorinated alcohols, but since all four estergroups are derived from fluorinated alcohols, these esters, too, aresymmetric. Other examples of the teaching of symmetrically fluorinatedmolecular structures include U.S. Pat. Nos. 4,203,856; 5,066,856 and4,039,301 and in JP08258482 and JP08259501.

Fluorine-containing tri-carbonyl compounds, including some esters, aredisclosed as lubricant additives in Japanese patent JP 07242584, andpartial fluoroesters of polycarboxylic acids, in which the acidfunctional groups are not completely esterified was taught in U.S. Pat.No. 3,124,533.

BRIEF SUMMARY OF THE INVENTION

In view of the above description of the prior art, it is an object ofthe present invention to provide a fluorinated lubricant additive whichcan serve as an anti-wear agent and friction reducer that is compatiblewith conventional lubricant base fluids and which overcomes the cost andsolubility limitations of highly fluorinated solid and liquid materials.This object has been achieved in non-symmetric, partially fluorinatedcompositions and compounds of the present invention.

Thus, the present invention provides a composition for use as alubricant or an additive to a lubricant formulation comprising anorganic molecular structure wherein said structure is a non-symmetric,partially fluorinated structure having backbone formed from alkylgroups, aromatic groups or mixtures of alkyl and aromatic groups, atleast two functional linkages joining end groups to the backbone and endgroups, wherein at least one end group is wholly or partiallyfluorinated and at least one other end group contains only atomsselected from the group consisting of hydrogen, carbon, nitrogen,oxygen, sulfur, phosphorous and chlorine.

The functional linkages of the present invention contain atoms selectedfrom the group consisting of oxygen, nitrogen, sulfur, and phosphorous.Preferred functional linkages include carboxylic esters, thioesters,sulfonic esters, ureas, thioureas, amides, phosphates, thiophosphates,imines, amines, ethers, thioethers, urethanes, thiourethanes,sulfoxides, and sulfones.

The present invention also provides a process for synthesizing thepresent composition comprising the steps of:

a) forming a reaction mixture containing components A and B which whenreacted form functional linkages wherein A is a mixture of two or morecompounds containing at least one reactive functional group selectedeither from the group consisting of alcohol, mercaptan and amine or fromthe group consisting of carboxylic acid, acid anhydride, acid chloride,carboxylic ester, nitrile, sulfonyl halide, isocyanate, isothiocyanate,aldehyde, ketone, alkyl halide, phosphoryl halide, thiophosphorylhalide, phosphoric anhydride, and thiophosphoryl anhydride, and furtherwherein at least one of said compounds of said mixture is a partiallyfluorinated compound and at least one other of said compound of saidmixture is a non-fluorinated compound; and wherein B is a compoundcontaining at least two reactive functional groups which are the same ordifferent and are capable of reacting with the reactive functionalgroups present in A and said reactive functional groups of B areselected either from the group consisting of alcohol, mercaptan andamine or from the group consisting of carboxylic acid, acid anhydride,acid chloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride; with the proviso: (i) that when the functional groups ofeither A or B are alcohols, then the functional groups of B or A,respectively, are selected from the group consisting of (ii) that whenthe functional groups of either A or B are mercaptans, then thefunctional groups of B or A, respectively, are selected from the groupconsisting of acid halide, isocyanate and alkyl halide; and (iii) thatwhen the functional groups of either A or B are amines, then thefunctional groups of B or A, respectively, are selected from the groupconsisting of carboxylic acid, acid anhydride, acid chloride, carboxylicester, isocyanate, aldehyde and ketone; and

b. reacting the mixture to form the functional linkages, and

c. recovering a non-symmetric, partially fluorinated composition havinga molecular structure:

 R_(1f)—F′—R₂—F″—R_(3h)

Where: R_(1f) represents a wholly or partially fluorinated C₁ to C₄₀organic residue end group; F′ and F″ represent functional linkages whichare either alike or different and are selected from the group consistingof carboxylic esters, thioesters, sulfonic esters, ureas, thioureas,amides, phosphates, thiophosphates, imines, amines, ethers, thioethers,urethanes, thiourethanes, sulfoxides, sulfones, and mixtures thereof; R₂represents the hydrocarbon backbone selected from the group consistingof a C₁ to C₃₀ alkyl, cycloalkyl, and aromatic group and mixturesthereof; and R_(3h) represents a non-fluorinated C₁ to C₄₀ organicresidue end group.

The preferred structures for component A useful in the present inventioninclude the following, where X represents an —OH, —SH, —NH₂ or —NHR′group:

F(CF₂)_(x)CH₂X; H(CF₂)_(x)CH₂X, wherein x is 1 to about 20; mixtures ofthe telomers of F(CF₂CF₂)_(x)CH₂CH₂X, wherein x is 1 to about 10 andpreferably having an average x of from about 3.5 to about 3.9; mixturesof the telomers of F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H, wherein x is 1 to about10 and y is 1 to 20 and preferably having an average x of about 3.9 andan average y of about 8, and of the telomers ofF(CF(CF₃)CF₂O)_(x)CF(CF₃)CH₂X, wherein x is 1 to about 12 and preferablyhaving an average x of about 6.7.

The preferred structures for component B useful in the present inventioninclude the difunctional carboxylic acid, acid anhydride, acid chloride,carboxylic ester, nitrile, sulfonyl halide, isocyanate, isothiocyanate,aldehyde, ketone, alkyl halide, phosphoryl halide, thiophosphorylhalide, phosphoric anhydride, and thiophosphoryl anhydride.

Diacids useful in the present invention include those having from about4 to 24 carbons, the corresponding acid anhydrides and dimer acidshaving up to 36 carbons. Acid halides, sulfonyl halides, isocyanates,isothiocyanates, phosphoryl halides and thiophosphoryl halides havingstructures corresponding to these diacids are also useful in the presentinvention. Although the preferred structures of the compounds of thepresent invention are the structures having like functional groups,structures may have mixed functional groups, for example, carboxylicacid/sufonyl halide, carbonyl/carboxylic acid or other combinations.

The present invention includes a lubricant composition comprising a basefluid mixed with the non-symmetric, partially fluorinated compounds ofthe present invention.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows friction and wear performance of ZDDP in 150N oil, for thepurpose of comparison with the reduction in friction and wear observedwith compositions and compounds of the present invention.

FIG. 2 shows BOCLE wear as a function of the mole percent of thefluorinated telomer alcohol in the mixed alcohol reactant of Example 1.

FIG. 3 shows BOCLE wear performance as a function of the weight percentof additive in 150N oil and as a function of the weight percent fluorinein the mixture of oil and additive the for the diester of Example 2prepared from reaction of Dodecanedioic acid (DDDA), telomer alcohol andExxal 13.

FIG. 4 shows wear performance of the diester additive of Example 3 as afunction of the weight percent of additive in 150N oil and as a functionof the weight percent fluorine in the mixture of oil and additive.

FIG. 5 shows a comparison of wear reduction of preparation 18, Example 3to that of a commercially available non-fluorinated ester additive as afunction of the weight percent of additive present in the additive/oilmixture.

FIG. 6 illustrates a triangular plot showing how the amount of insolublesolids (i.e., residue) varies with the composition of the mixedamide-esters derived from primary amines of Example 6.

FIG. 7 illustrates a triangular plot showing how the amount of insolublesolids (i.e., residue) varies with the composition of the mixedamide-esters derived from secondary amines of Example 6.

FIG. 8 shows wear performance of the diester additive of Example 7 as afunction of the weight percent of additive in 150N oil and as a functionof the parts per million of fluorine in the mixture of oil and additive.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a composition for use as a lubricant oran additive to a lubricant formulation comprising an organic molecularstructure wherein said structure is a non-symmetric, partiallyfluorinated structure having backbone formed from alkyl groups, aromaticgroups or mixtures of alkyl and aromatic groups, at least two functionallinkages joining end groups to the backbone and end groups, wherein oneend group is wholly or partially fluorinated and the other end groupscontain only atoms selected from the group consisting of hydrogen,carbon, nitrogen, oxygen, sulfur, phosphorous and chlorine. For example,a molecular structure of the present invention may be illustrated asfollows:

R_(1f)—F′—R₂—F″—R_(3h)

where R_(1f) represents a wholly or partially fluorinated organicresidue end group, F′ and F″ represent functional linkages which may bealike or different, R₂ represents the backbone and R_(3h) represents anon-fluorinated organic residue end group. The compounds correspondingto this molecular structure are defined for purposes of this inventionas being non-symmetric, partially fluorinated structures.

The functional linkages of the present invention contain atoms selectedfrom the group consisting of oxygen, nitrogen, sulfur, and phosphorous.Preferred functional linkages include carboxylic esters, thioesters,sulfonic esters, ureas, thioureas, amides, phosphates, thiophosphates,imines, amines, ethers, thioethers, urethanes, thiourethanes,sulfoxides, and sulfones.

The preferred structures of the present invention include compoundswhere F and F′ is the same linkage. R_(1f) and R_(3h) may be, but neednot be alike.

By non-symmetric, partially fluorinated structure is meant an organiccompound having some of the hydrogen replaced by fluorine and having thefluorine concentrated in one region of the structure. For example, thefollowing is a structure for a diester according to the presentinvention, R_(f)(CH₂)_(x)O₂C—R—CO₂R_(h), where R_(f) is a partly orcompletely fluorinated group, R_(h) is a non-fluorinated group, and x≧1.Such diesters synthesized according to the process of the presentinvention may also contain non-fluorinated diesters,R_(h)O₂C—R—CO₂R_(h), and symmetrically-fluorinated diesters,R_(f)(CH₂)_(x)O₂C—R—CO₂(CH₂)_(x)R_(f) byproducts. In terms of structuralcomponents, R_(f) and R_(h) are end groups —R— is the backbone and —O₂C—is the functional linkage. The preferred backbone is formed from ahydrocarbon chain which may be alkyl, aromatic, or a mixture of alkyl(branched, cyclic or straight chains) and aromatic units. It ispreferred that unsaturation such as alkylene groups in the backbone beavoided if the additive is to be stable under conditions of use. Itshould be further appreciated that the backbone can optionally containmore than two functional groups and as such other B molecules such asneopentyl glycol, trimethylolproprane, pentaerythritol, and the like arecontemplated as being useful in the present invention.

The term base fluid means a lubricating material, liquid or solid usedas the major component in a lubricant formulation. Base fluids arecombined with other substances to make fully formulated lubricants foruse in reducing friction and wear. A base fluid may be synthetic ornatural.

The non-symmetric, partially fluorinated compounds of the presentinvention may be derived, for example in the case of an ester, from adiacid, at least one partially fluorinated alcohol, R_(f)OH, and atleast one non-fluorinated alcohol, R_(h)OH, or their functionalequivalents. In this shorthand, R_(f) represents a partially or whollyfluorinated group and R_(h) represents a non-fluorinated group. Thefunctional linkage is the —COO— group forming the ester. The diesteraccording to the present invention is a mixture of at least 3 genericcomponents: R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f),R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(h), and R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(f).Since in commercially available compounds R_(f)OH and R_(h)OH arethemselves generally mixtures, the diester products are even morecomplicated mixtures containing all possible combinations of R_(f) andR_(h). That is, each of the three generic components is itself amixture. R_(f) is derived from the partly-fluorinated alcohol, R_(h)from the non-fluorinated alcohol, and the central part of the diester,—O(O)C—(CH₂)_(x)—C(O)O— can be thought of as derived from a diacid,HO(O)C—(CH₂)_(x)—-C(O)OH.

The diester simply serves as an example of one of the many compounds ofthe present invention. Other functional linkages may be formed in thesame fashion as the ester functional linkage by proper selection of thereaction components. For example, one component may be represented by“A” and the other by “B”. The functional linkages are formed in thereaction of A with B. In all cases A represents a mixture of the classor classes of compounds that are to be reacted with B; and A is amixture of two or more compounds wherein at least one of these compoundsis a partially fluorinated compound and the other compounds arenon-fluorinated compounds; with the proviso that when A is a mixture ofalcohols, B is an selected from the group consisting of diacids anddiacid equivalents, nitrites, sulfonyl halides, isocyanates,isothiocyanates, phosphoryl halides and thiophosphoryl halides; when Ais a mixture of mercaptans, B is selected from the group comprisingcarboxylic acid halides, isocyanates and alkyl halides; and when A is amixture of amines, B is selected from the group consisting of carboxylicacids and acid equivalents, isocyanates, aldehydes and ketones.

Again for illustration considering the reaction of a mixture of alcohols(A) with a diacid or mixture of diacids (B), theoretically when analcohol mixture that is 50 mole percent non-fluorinated alcohol and 50mole percent fluorinated alcohol, the mole percent composition of themixed diester product is 50 mole percent non-symmetric, partiallyfluorinated diester, and 25 mole percent each symmetrically fluorinateddiester and hydrocarbon diester. As the composition of the alcoholmixture is changed with respect to the ratio of fluorinated tonon-fluorinated alcohol, the composition of the ester mixture resultingfrom the reaction changes according to the probability of producingdiesters of symmetric and non-symmetric structures. The inventor hasfound that the presence of the non-symmetric, partially fluorinateddiester in the mixed ester product of amounts as low as 1 mole percentproduces dramatic reduction in friction when the mixture is used aloneor formulated into a base fluid. That is to say that a mixturecontaining 1 mole percent of the compound of the present invention,present in a lubricant equal to about 0.2% fluorine content in theoverall lubricant formulation, results in a dramatic reduction infriction and wear. Also any composition of a resulting diester mixture,or other mixtures of the present invention, may be adjusted to reducethe amount symmetric, fluorinated diester present by dewaxing thecomposition, as is illustrated in the Examples below. End groups,backbones and function linkages of the present invention may be selectedaccording to the listing below. This listing is not exhaustive, butlists examples of functional linkages which provide ligands for metalsurfaces. For example, metal compositions present at typical steelsurfaces might comprise iron and various iron oxides as well as othermetals and oxides from other metallic components present in the steelalloy (most commonly other first-row transition metals, notably Cr andNi, though second-row and third-row metals may also be present).Effective ligands for such metal compositions include organic compoundscontaining atoms with unshared electron pairs which can serve as Lewisbase electron-pair donor ligands to form donor-acceptor bonds with metalcompositions. Thus, suitable functional linkages include any functionallinkage that forms an effective ligand with the surface of the substratethat is to be lubricated. In a sense the structures of the presentinvention may be thought of as a combination of a high lubricityfluorinated end, a functional linkage that both connects the end to thebackbone of the structure and forms a ligand-like association with thesurface to be lubricated and a hydrocarbon tail which providessolubility in the base fluid.

Selection of Structural Components

Functional Group 1 Functional Group 2 F Linkage Alcohol Carboxylic acid,acid Carboxylic anhydrides, carboxylic ester esters, nitrile, orcarboxylic acid halide (e.g. chloride) Mercaptan Carboxylic acid halideThioester (e.g. chloride) Alcohol Sulfonyl halide (e.g. Sulfonic esterRSO₂Cl) Alcohol Isocyanate Carbamates (Urethanes) Alcohol IsothiocyanateThiourethane Amine Isocyanate Urea Mercaptan Isocyanate Thiourea AmineCarboxylic acid, Amide Carboxylic acid halide or ester AlcoholPhosphoryl halide (e.g. Phosphate (O chloride) donor atoms) AlcoholThiophosphoryl halide Thiophosphate (e.g. chloride) (S or O donor atoms)Amine Carbonyl compound Imine, amine (aldehyde or ketone) (afterreduction) Alcohol Alkyl halide Ether Mercaptan Alkyl halide Sulfide(Thioether) Alcohol Phosphoric anhydride Dialkylphosphor- ic acid esterAlcohol Thiophosporic anhydride Dialkyl dithiophosporic acid esterOxidation of sulfides Sulfoxides and (see above) Sulfones

The previously known, symmetrical, highly-fluorinated compounds, forexample, diesters, R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f), have low solubilityin the mineral oils commonly used as lubricant base fluids and poorlow-temperature properties, which limits their use as lube additives. Itis the mixed, non-symmetric, partially fluorinated diesters,R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(f), which is the main object of thisinvention. However, it is generally not necessary to separate thedesired non-symmetric, partially fluorinated diesters from the highlyfluorinated and non-fluorinated diesters products also present in thereaction mixture.

Although usually not necessary, if desired, the mixed products of thepresent invention may be purified by centrifugation, distillation,fractional crystallization, filtration, extraction, or other standardmethods known to those skilled in the art.

Preparation of the compositions of the present invention may beachieved, for example by 1) preparing the compounds of the inventionusing a limited, less than stoichiometric, amount of fluorinatedcomponent in the synthesis and 2) preparing the compounds of the presentinvention from a mixture of at least one fluorinated “A” compound andone non-fluorinated “A” compound, preferably a mixed-isomer, long-chain,non-fluorinated component of class “A”.

The process of the present invention comprises the steps of:

a) forming a reaction mixture containing components A and B which whenreacted form functional linkages wherein A is a mixture of two or morecompounds containing at least one reactive functional group selectedeither from the group consisting of alcohol, mercaptan and amine or fromthe group consisting of carboxylic acid, acid anhydride, acid chloride,carboxylic ester, nitrile, sulfonyl halide, isocyanate, isothiocyanate,aldehyde, ketone, alkyl halide, phosphoryl halide, thiophosphorylhalide, phosphoric anhydride, and thiophosphoryl anhydride, and furtherwherein at least one of said compounds of said mixture is a partiallyfluorinated compound and at least one other of said compound of saidmixture is a non-fluorinated compound; and wherein B is a compoundcontaining at least two reactive functional groups which are the same ordifferent and are capable of reacting with the reactive functionalgroups present in A and said reactive functional groups of B areselected either from the group consisting of alcohol, mercaptan andamine or from the group consisting of carboxylic acid, acid anhydride,acid chloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride; with the proviso: (i) that when the functional groups ofeither A or B are alcohols, then the functional groups of B or A,respectively, are selected from the group consisting of carboxylic acid,acid anhydride, acid chloride, carboxylic ester, acid anhydride,nitrile, sulfonyl halide, isocyanate, isothiocyanate, phosphoryl halide,thiophosphoryl halide and alkyl halide; (ii) that when the functionalgroups of either A or B are mercaptans, then the functional groups of Bor A, respectively, are selected from the group consisting of acidhalide, isocyanate and alkyl halide; and (iii) that when the functionalgroups of either A or B are amines, then the functional groups of B orA, respectively, are selected from the group consisting of carboxylicacid, acid anhydride, acid chloride, carboxylic ester, isocyanate,aldehyde and ketone; and

d. reacting the mixture to form the functional linkages, and

e. recovering a non-symmetric, partially fluorinated composition havinga molecular structure:

R_(1f)—F—R₂—F′—R_(3h)

Where: R_(1f) represents a wholly or partially fluorinated C₁ to C₄₀organic residue end group; F and F′ represent functional linkages whichare either alike or different and are selected from the group consistingof carboxylic esters, thioesters, sulfonic esters, ureas, thioureas,amides, phosphates, thiophosphates, imines, amines, ethers, thioethers,urethanes, thiourethanes, sulfoxides, sulfones, and mixtures thereof; R₂represents the hydrocarbon backbone selected from the group consistingof a C₁ to C₃₀ alkyl, cycloalkyl, and aromatic group and mixturesthereof; and R_(3h) represents a non-fluorinated C₁ to C₄₀ organicresidue end group.

The reaction used to form the functional linkage from components A and Bmay be any of the methods known in the art. In some cases particularreaction methods may be more favorable because of rate, and or theability to remove unwanted byproducts such as water.

As the fluorinated component of the mixture “A”, alcohols may be moreeasily found since there are several types commercially available.Examples of common partly-fluorinated alcohols useful in the presentinvention include 1H, 1H, 2H, 2H-perfluoroalkanols, whereF(CF₂CF₂)_(x)CH₂CH₂OH, are preferred, with mixtures where x is at least1; F(CF₂)_(x)CH₂OH alcohols, for example, 1H, 1H-heptafluoro-1-butanol;and 1H, 1H-perfluoro-1-octanol; H(CF₂)_(x)CH₂OH alcohols, for example,1H, 1H, 5H-octafluoro-1-pentanol; F(CF₂CF₂)_(x)CH₂CH₂OH alcohols, forexample, 1H, 1H, 2H, 2H-perfluoro-1-octanol mixtures with average x ofabout 3.5 or about 3.9 (referred to as Telomer alcohol-L and Telomeralcohol respectively); F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H, generally mixtureswith average x of about 3.9 and y about 8, for example, Telomerethoxylate alcohol; and F(CF(CF₃)CF₂O)_(x)CF(CF₃)CH₂OH, generallymixtures with average x of about 6.7, for example, poly HFPO alcohol. Inthe present process one may also use as components of the mixture “A”,mercaptans or amines having structures similar to or derived from theavailable alcohols; for example, F(CF₂CF₂)_(x)CH₂CH₂SH and F(CF₂CF₂)_(x)CH₂CH₂CH₂NH₂.

Virtually any non-fluorinated compound of class “A” may be used toprepare the non-symmetric, partially fluorinated compounds of thepresent invention. The non-fluorinated alcohols preferred for thisinvention are those commonly used in lubricant ester fluids, typicallyhigher aliphatic alcohols such as those described in Kirk Othmer, Volume1 (1991). These include mixtures, such as Exxal 13, tridecyl alcohol,manufactured by Exxon, indicated on the Material Safety Data Sheet to be“Alcohols, C11-C14, iso.” Such alcohols produce esters with desirablephysical properties to be used as lubricants and lubricant additives.

In the cases where amines or mercaptans serve as the non-fluorinatedcomponent of mixture “A”, one may use any suitable amines or mercaptans.Those having structures corresponding to or derived from the availablealcohols described in the paragraph immediately above are preferred.

The preferred diacids for the present invention are those diacidscommonly used in forming lubricant ester fluids. These are most commonlystraight chain diacids, HO(O)C—(CR₂)_(x)—C(O)OH, wherein each R isindependently selected from H or C₁ to C₄ alkyl group. Most commonly,all R=H and x=1 to about 12. The most available and widely used diacidsare adipic, azelaic, sebacic, and dodecanedioic acids, which contain 6,9, 10, and 12 carbons respectively. However branched structures such as2-methylglurtaric acid are acceptable. Also, two or more R may beconjoined to form cyclic structures such as in C₃₆ “dimer acid.”Mixtures of diacids may be used, such as C₃₆ “dimer acid” or CORFREE®M1, from Dupont, which is a mixture of mainly C₁₀-C₁₂ diacids. Preferreddiacids include adipic, 2-methylglutaric, 2-ethylsuccinic, CORFREE M1and longer chain acids such as Dodecanedioic acid (DDDA). Selection ofdiacid and other “B” group chain lengths will depend on the lubricantapplication for which the additive is to be used. In liquid lubricantformulations the “B” group chain length, in combination with thenon-fluorinated “A” group is selected so that the additive is soluble inthe liquid base fluid. For solid lubricants, the chain lengths can besuch that the additive is either a liquid or solid, which is soluble orcompatible with the base fluid. It may even be desirable to use acomposition of the present invention alone as a lubricant.

It should be further appreciated that either A or B or both may beoptionally substituted with functional groups which do not interfere inthe reaction of A with B to form the desired functional linkages. Forexample, the respective components may contain ether linkages, such asin ethoxylated or propoxylated animes or alcohols, or ether amines suchas ROCH₂CH₂CH₂NH₂. They may also contain linear, branched or cyclicarrangements of atoms and may contain more than one branched groups thatmay be the same or different.

TEST METHODS

Samples were tested using the ball-on-cylinder (BOCLE) test, describedin ASTM D5001. Wear was quantified by the size of the wear scar on theball, measured at the end of the test. A smaller wear scar indicatedless wear. The coefficient of friction was calculated from the ratio ofthe tangential (lateral) force on the ball to the downward (normal)force on the ball. In all cases, the normal force was 12,00 grams (seeTable 1). Several modifications were made to the test, as summarized inTable 1. These changes are expected to make the test a more severe testof anti-wear and friction modifying properties, as described below.

TABLE 1 Ball-on-cylinder test conditions. Standard ASTM D5001 ModifiedD5001 (consequence) 0.5″ ball 0.25″ ball (smaller contact area) 25° C.80° C. (lower lubricant viscosity) 1000 g load, 30 500 g break in load,0.5 minute, minutes followed by 6000 g test load, 30 minutes (highercontact pressure; note that a 6000 g load produces a 12,000 g normalforce at the ball- cylinder contact point) No friction data Calibratedload cell to measure tangential force on ball during test (allowscalculation of coefficient of friction from ratio of tangential force tonormal force, 12,000 g)

The relative performance of the materials of the present invention wasevaluated as additives in a mineral oil base fluid. A commonly availablehigh-quality solvent-refined 150 neutral oil (150N) available fromConoco (about ISO 32 viscosity grade) was selected as the mineral oilbase fluid. A grade of oil such as 150N might be used as one componentfor blending of an oil for use in an internal combustion engine. 150Ncontains no additives. This 150N oil was tested according to themodified BOCLE method numerous times, the average of these results issummarized in Table 2.

TABLE 2 Solvent refined 150N oil BOCLE results Solvent-refinedCoefficient of Wear scar, 150N oil friction mm Number of 9 13measurements Average 0.1424 0.851 Standard 0.0052 0.042 deviation 95%Confidence ±0.00399 ±0.025 interval

For comparative purposes, the friction and wear performance of severalfully formulated (ILSAC GF-1), commercially available passenger carmotor oils were measured. The oils tested included two leading fullsynthetics (MOBIL 1 5W30, Castrol SYNTEC 5W50) and one conventionalnon-synthetic oil (MOTORCRAFT 5W30). Performance of all three oils wasvery similar, as summarized in Table 3. This may be because all threecontain similar amounts of zinc dialkyldithiophosphate (ZDDP), anextremely effective anti-wear agent. The effect of varying concentrationof ZDDP (“Elco 106” purchased from Ideas, Inc.) is shown in FIG. 1. Thedata in this Figure serves as to provide a standard for comparison ofthe improvement in lubrication achieved by mixing a hydrocarbonlubricant with the non-symmetric partially fluorinated compositions ofthe present invention.

TABLE 3 Commercially Available GF-1 Motor Oil BOCLE Test ResultsFormulated GF-1 Coefficient of Wear Motor oils friction scar, mm Numberof 2 9 measurements Average 0.1313 0.499 Standard 0.0029 0.029 deviation95% Confidence ±0.0260 ±0.022 interval

To determine the efficacy of the additives made according to the presentinvention, their effect on friction and wear was measured as a functionof their concentration in the standard 150N oil. Note that there are twoapproaches to obtaining a given level of fluorine in a blendedlubricant. An additive containing a high level of fluorine can be usedat a low treat rate or an additive containing a low level of fluorinecan be used at a high treat rate. These two approaches do notnecessarily give the same performance.

The following Examples illustrate the present invention, but are notintended to be limiting.

EXAMPLE 1

The following Example describes the condensation esterification of DDDAusing Fascat 2003 catalyst, a tin-based esterification catalyst from ElfAtochem, and the preparation of DDDA diesters with varying mole percentTelomer alcohol and Exxal 13.

Reaction mixtures were prepared in 20 mL vials with the compositionsindicated in table 4 below. One drop of Fascat 2003 (a product ofAtochem) was added to each vial, and the reactions were heated at200-250° C. for about 12 hours under a nitrogen sweep to remove evolvedwater. GC analysis of the reaction mixtures showed the expected threecomponent ester mixture: R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f);R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(h); and R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(f).The actual amount of each ester component present varied as expectedwith the relative amounts of Telomer alcohol and Exxal 13 present in thesynthesis mixture. The appearance of the mixture formed from therespective additive and 150N oil as well as the solubility of theadditive in 150N oil are also summarized in the Table 4. It isnoteworthy that the fully fluorinated diester, vial 8, was more solublewhen heated, but that the solution cooled to a gel-like state as thediester reprecipitated with cooling. Such behavior is very undesirablein a lubricant. This illustrates an important deficiency of the fullyfluorinated diesters, since lubricants are often subjected totemperature cycling, and low-temperature performance is often critical.

TABLE 4 DDDA diesters with Telomer alcohol and Exxal 13 mol % TelomerSolubility in Telomer Exxal alcohol 150 N DDDA alcohol 13 vs total oilat No. (mmol) (mmol) (mmol) alcohol Appearance 25° C. 1 5.15 0.29 10.743 liquid ≧20% 2 4.94 0.58 10.51 5 liquid 3 5.15 1.34 9.88 12 honey- >1%like 4 5.05 2.4 8.81 21 very thick oil 5 5.05 4.4 6.62 40 grease ≦0.5%like 6 5.13 5.62 5.47 51 grease ≈0.25% like 7 5.15 8.26 2.78 75 beeswaxlike 8 5.34 11.06 0 100 paraffin ≦0.1% like

Wear test results for some of the above materials are shown in FIG. 2.It is clear from this figure that most of the wear benefit is achievedwith only about 20 mole % Telomer alcohol in the diester. The wearresponse, quite surprisingly, is extremely non-linear. This is contraryto the linear response that might be expected if the wear-reducingeffects were simply the net average from the concentration present ofcompletely fluorinated diester (100% Telomer alcohol) andnon-fluorinated ester (0% Telomer alcohol). This implies that thenon-symmetric, partially fluorinated diesters of the present inventionhave better wear reducing properties than either the non-fluorinated orcompletely fluorinated diesters.

EXAMPLE 2

The following Example describes the condensation esterification of DDDAusing p-toluenesulfonic acid catalyst and the preparation of DDDAdiester using a mixture of 50 mole % Telomer alcohol and 50 mole % Exxal13 followed by a “dewaxing” hexane extraction to remove thesymmetrically fluorinated component from the mixed ester product.

A mixture of 230.3 g DDDA (1.0 mole), 474.64 g Telomer alcohol (1.05mole), 207.91 g Exxal 13 (1.05 mole), and 1.9 g p-toluenesulfonic acid(0.01 mole) were charged to a reactor fitted with a Dean-Stark trap andcondenser. The Dean-Stark trap was filled with additional Exxal 13. Thereaction was heated and sparged with nitrogen to remove water. Thenitrogen sparge was removed and the reaction heated to 280° C. undervacuum (≦0.07 kPa). A portion of the crude ester (610 g) was stirredwith 1700 g hexane. The hexane solution was decanted and filtered fromundissolved, highly fluorinated material. The hexane solution wastreated with activated charcoal and filtered, then with basic aluminaand filtered again. Hexane was removed by distillation. Elementalanalysis of the residue showed 29.56% F, in good agreement with 28.3% Fby ¹H NMR analysis.

FIG. 3 shows the wear performance of this high-F-content material in150N oil. The range of fluorine concentrations shown in FIG. 3corresponds to weight concentrations of diester ranging up to 1%.Samples of 150N containing 0.25% diester (equivalent to 0.07%F) or morewere hazy at ambient temperature, due to the limited solubility of thehighly fluorinated diester component, R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f),but were homogeneous at the 80° C. BOCLE test temperature. The responseis very non-linear. A very strong anti-wear effect is obtained with onlyvery small concentrations of the additive. The properties of the mixtureof 150N oil and additive are much better than the properties expectedbased on simple linear effects and overall composition. The anti-wearperformance achieved in FIG. 3, through use of the non-symmetrical,partially fluorinated diesters of the present invention, without otheradditives, is comparable to that of fully formulated motor oil.

EXAMPLE 3

The following Example describes the condensation esterification of DDDAusing methanesulfonic acid catalyst and the preparation of DDDA diesterusing a mixture of 50 mole % Telomer alcohol-L and 50 mole % Exxal 13.

A 500 mL round bottom flask was charged with 69.06 g DDDA (MW 230.3, 0.3mole), 130.41 g Telomer alcohol-L (average molecular weight≈414, 0.315mole), 62.37 g Exxal 13 tridecyl alcohol from Exxon (FW≈198, 0.315mole), 0.29 g methanesulfonic acid (MW 96.1, 0.003 mole), and 100 gmixed xylenes. The reaction flask was fitted with an 8″ Vigreux columntopped with a Dean-Stark trap and condenser. The reaction was heated toreflux to drive off water, which was separated in the Dean-Stark trap,xylene overflow being returned to the reaction flask. The reaction wasfollowed by water removal and by periodic sampling and titration foracid number.

After 10 and ½ hours reaction time, the acid number had decreased to 1.6mg KOH/g, and the reaction was considered to be complete.

The reaction product was brown. The reaction product was washed, at70-80° C., with 330 g of 0.2% aqueous sodium hydroxide. Phases wereinverted, with a brown aqueous phase on top and the denser ester phaseon the bottom. The lower ester phase was very cloudy. After separatingthe caustic wash, the ester phase was washed three times with 300 mLportions of warm water. The acid number was 0.56 mg KOH/g.

The crude ester was sparged with nitrogen and heated from roomtemperature to a temperature of 210-220° C. over a period of 90 minutesto remove xylene, water, and other low boilers.

The yield was 215.72 g of a waxy tan solid having an acid number 0.75 mgKOH/g.

The same basic procedure as above was used to prepare other partiallyfluorinated esters, listed in Table 5. In all cases, the non-fluorinatedalcohol was Exxal 13, tridecyl alcohol from Exxon. Due to difficultyobtaining reliable F elemental analysis, ester end groups were alsoanalyzed by ¹H NMR. The chemical shift region between 3.5 and 4.5 ppmdownfield of tetramethylsilane reveals the CH₂ protons attached to theester oxygen. In the case of R_(f), these CH₂ protons are cleanlyseparated and downfield from the CH₂ protons of R_(h). The relativemolar amounts of R_(f) and R_(h) can be calculated from the integrals ofthese two groups. Where elemental analysis and NMR disagree, the NMRmethod is believed to be more reliable. Table 5. Partially fluorinatedesters prepared by condensation esterification using methanesulfonicacid catalyst

Mole fraction Acid Partially partially number Wt % F Wt % Prepara-Fluorinated fluorinated (mg (elemental F (by tion Diacid alcohol alcoholKOH/g) analysis) NMR) 9 Adipic Telomer 0.025 0.34 1.92 2.6 alcohol-L 10Adipic Telomer 0.025 0.29 2.25 3.2 alcohol 11 Azelaic Telomer 0.025 01.83 1.66 Alcohol-L 12 C14 Telomer 0.025 0.27 1.39 1.28 diacid alcohol-L13 Corfree Telomer 0.025 0 1.23 1.39 M1 alcohol-L 14 Corfree Telomer0.025 0.6 1.32 1.49 M1 alcohol-L 15 DDDA Poly HEPO 0.025 0.1 4.17alcohol 16 DDDA Telomer 0.025 alcohol 17 DDDA Telomer 0.025 0.55 2.1 2.4alcohol 18 DDDA Telomer 0.025 0.13 1.86 2 alcohol 19 DDDA Telomer 0.0230.1 0 0 alcohol 20 DDDA Telomer 0.024 0 0 0 alcohol 21 DDDA Telomer0.025 0.18 1.87 2.1 alcohol-L 22 DDDA Telomer 0.125 0.24 3.01 9.47alcohol-L 23 DDDA Telomer 0.05 0.2 4.06 alcohol-L 24 DDDA Telomer 0.0250.18 1.82 1.92 alcohol-L 25 DDDA Telomer 0.25 0.3 16.68 17.3 alcohol-L26 DDDA Telomer 0.5 0.751 34.6 34.3 alcohol-L 27 DDDA Telomer 0.025 0.272.36 3.4 ethoxylate alcohol 28 Sebacic Telomer 0.025 0.2 1.58 1.63alcohol-L 29 Suberic Telomer 0.025 0.26 0.72 1.91 alcohol-L

FIG. 4 shows the wear and friction performance of a low-F-contentmaterial (≈2% F), sample 18 in Table 5, in 150N oil. This low-F-contentmaterial was completely soluble even at 20% by weight concentration (0.4wt. percent F). FIG. 5 compares the anti-wear performance of this low-Fmaterial to a similar non-fluorinated diester, ditridecyl dodecanedioate(Hatcol 2907, from Hatco), showing the significant improvement in wearperformance from only a very small amount of F incorporation.

Anti-wear and friction reducing performance of different chain lengthdiesters from C₆ to C₁₄ was compared. All of these non-symmetric,partially fluorinated diesters imparted some benefits, with the longerchain diacids giving the greater benefits. Therefore, the preferrednumber of carbon atoms in the backbone is 9 or more or the wear scar bythe BOCLE test as described herein is less than about 0.75 when theadditive is present at about 0.2% fluorine.

EXAMPLE 4

The following Example describes the transesterification of dimethyldodecanedioate using p-toluenesulfonic acid catalyst and the preparationof DDDA diester using a mixture of 50 mole % Exxal 13 and 50 mole % 1H,1H, 5H-octafluoro-1-pentanol.

A mixture of 51.68 g dimethyl dodecanedioate (0.2 mole), 41.58 g Exxal13 (0.21 mole), 48.73 g 1H, 1H, 5H-octafluoro-1-pentanol (0.21 mole),and 0.38 g p-toluenesulfonic acid was heated, and methanol distilledoff. When the reaction temperature reached 198° C., GC analysis showedthe dimethyl dodecanedioate to be essentially gone, indicating that thereaction had gone nearly to completion. After cooling, the product waswashed with brine, 1% aqueous NaOH, and water, then treated with basicalumina and filtered. The final acid number was ≦0.1 mg KOH/g.

The same basic procedure was used to prepare other diesters, listed inTable 6. The non-fluorinated alcohol was Exxal 13 in all cases.

TABLE 6 DDDA diesters prepared according to Example 4. Mole fractionAcid Partially partially number Wt % F Wt % F Prepara- Fluorinatedfluorinated (mg (elemental (by tion alcohol alcohol KOH/g) analysis)NMR) 30 Telomer 0.025 1.12 1.24 alcohol-L 31 1H, 1H, 5H- 0.5 0.1octafluoro-1- pentanol 32 1H, 1H, 2H, 0.5 0.1 2H-perfluoro- 1-octanol 331H, 1H 0.5 0.1 heptafluoro- 1-butanol 34 1H, 1H- 0.5 0.1 perfluoro-1-octanol 35 Telomer 0.025 2 alcohol 36 Telomer 0.025 0.52 1.45 1.63alcohol

Comparative Example 1

The following comparative Example describes the preparation ofdi(telomer alcohol)2-methylglutarate by one-step esterification of2-methylglutaronitrile (MGN).

A mixture of 32.44 g MGN (0.3 mole), 18.05 g water (1 mole), and 304.2 gTelomer alcohol (0.67 mole) was preheated to 60° C., then 60.0 gsulfuric acid (0.61 mole) was added cautiously. The H₂SO₄ was added over≈30 minutes to maintain reflux. After the acid was added, the reactionwas refluxed for an additional 3 hours. The crude ester was decantedfrom the ammonium bisulfate salt phase while warm, then washed with 5%aqueous sodium bicarbonate. The product was dried by heating to ≈100° C.under reduced pressure (≈0.1 kPa). The product was a tan, waxy solidwith a wide melting range (≈45-70° C.). Solubility in 150N oil was foundto be only ≦0.1% at ambient temperature.

EXAMPLE 5

This Example describes the esterification of 2-methylglutaronitrile(MGN) in a Two-step Reaction:

A mixture of 43.26 g MGN (0.4 mole) and 36.0 g water (2 mole) waspreheated to 85° C. Sulfuric acid (80.42 g, 0.82 mole) was added viadropping funnel, at a rate adjusted to maintain reaction temperature at115-135° C. Following the addition, the reaction was held at temperaturefor 1 hour, then cooled to 100° C. A mixture of 9.49 g Telomer alcohol(0.021 mole) and 162.16 g Exxal 13 (0.819 mole) was added over 7minutes, then the reaction was heated and held in the range 127-135 for1 hour. After cooling, the crude ester was decanted from ammoniumbisulfate salts. The crude ester was mixed with 100 g mixed xylenes and0.38 g methanesulfonic acid, placed in a reactor fitted with a Vigreuxcolumn and Dean-Stark trap, and heated to reflux to drive off water tocomplete the esterification. The reaction was sampled periodically andacid number determined. When the acid number had leveled off, indicatingthat no further reaction was occurring, the heat was turned off. Theproduct was washed with an equal volume of 0.5% NaOH solution, then 5times with water. Warming the mixture to 60° C. during the water washesimproved phase separation. The washed ester was sparged with nitrogenwhile being heated to 200° C. to drive off water. The final acid numberwas 0.15 mg KOH/g.

2-Methylglutarate diesters prepared according to Comparative example 1and example 5 are summarized below in Table 7. In all cases, thenon-fluorinated alcohol was Exxal 13.

TABLE 7 Mole fraction Acid Partially partially number Wt % F Wt % FPrepara- Preparation fluorinated fluorinated (mg (elemental (by tionmethod alcohol alcohol KOH/g) analysis) NMR) 37 5 Telomer 0.025 0.151.98 2.06 alcohol 38 5 Telomer 0.025 0.19 1.13 1.2 alcohol-L 39Comparative Telomer 0.5 0.07 example 1 alcohol 40 Comparative Telomer 1example 1 alcohol 41 5 Telomer 0.05 2.4 1.16 2.9 alcohol-L 42 5 Telomer0.125 0.3 5.33 8.56 alcohol-L

The following examples 6 and 7 show that partially-fluorinatedamide-esters can be prepared which have solubility in conventionalmineral oil and that these partially fluorinated amide-esters can beused as lubricant additives to reduce friction and wear.

EXAMPLE 6

Preparation and Solubility of Partially-Fluorinated Amide-Esters fromDodecanedioic Acid, Tridecyl Alcohol, and Zonyl BA Partially-FluorinatedAlcohol:

A set of screening experiments was conducted to preparepartially-fluorinated amide-esters from dodecanedioic acid (DDDA) forassessing their solubility in non-polar, non-hydrogen-bonding solventssuch as mineral oils The alcohols used in this series of reactions weretridecyl alcohol (Exxal 13 from Exxon) and the partially-fluorinatedalcohol, Zonyl BA (from Dupont). Several amines were used, includingArmeen 2HT, Armeen HTMD, and Armeen 18D (from Akzo Nobel Chemicals) andAdogen 101, and Adogen 140 (from Sherex/Witco). These amines aredescribed in table 8 below.

TABLE 8 Amine (CAS Description (type of amine, formula number) estimatedfrom ¹H NMR) Armeen 2HT Di (hydrogenated tallowalkyl)amine (R₂NH,(61789-79-5) average R = C_(17.6)H_(36.2)) Armeen HTMD Hydrogenatedtallowalkylamine (RNH₂, (61788-45-2) average R = C_(17.5)H₃₆) Armeen 18D(124- Octadecyl amine (RNH₂, R = C₁₈H₃₇) 30-1) Adogen 101 C₁₆-C₂₂ amine(RNH₂, average R = C_(20.3)H_(41.6)) (68037-92-3) Adogen 140Hydrogenated tallowalkylamine, also (68037-91-2) indicated to be C₁₄ toC₁₈ amine (RNH₂, average R = C_(18.1)H_(37.2))

Each reaction employed 1 mmol of DDDA, but the amounts of the otherreactants were systematically varied as follows. The mole ratio of Exxal13/DDDA was varied between 0 and 1.34, the mole ratio of Zonyl BA/DDDAwas varied between 0 and 1, and the mole ratio of amine/DDDA was variedbetween 0.33 and 2.0, under the constraint that the mole ratio of thetotal amount of alcohol and amine together was restricted to thetheoretically-required 2.0 moles per mole DDDA.

More specifically, for the case where the amine tested was Armeen 2HT,the following eight reaction mixtures in table 9 were prepared, wherethe numbers represent the amount of each ingredient used, in mmol(except for the methanesulfonic acid esterification catalyst, which wasused in 10 μl quantity in each mixture).

TABLE 9 Rx Rx Rx Rx Rx Rx Rx Rx Ingredient #1 #2 #3 #4 #5 #6 #7 #8 DDDA1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Exxal 13 0.66 1.34 0.67 0.5 1.34 ZonylBA 0.66 0.33 0.66 1.0 1.0 Armeen 1.34 1.34 0.33 0.67 1.0 0.5 0.66 2.02HT Methanesu- 10 10 10 10 10 10 10 10 lfonic μl μl μl μl μl μl μl μlacid (catalyst)

A similar set of eight reactions was prepared for each of the fiveamines tested, for a total of 40 reaction mixtures.

The reaction mixtures were prepared in 2 mL glass vials. Reactions wereconducted by placing the open-topped vials in a heated block maintainedat 150° C. and maintaining that temperature for at least 18 hours(generally 18-24 hours). This was intended to allow escape of waterformed from the esterification and amidation reactions. The crudereaction products were used without purification for solubility testing.

Relative solubility of the products from these reactions was assessed bymixing the reaction product with 30 ml tetrahydrofuran (THF), thencollecting and weighing any undissolved material on a 0.2 μmTeflon®-coated fiberglass membrane filter. The products from Armeen HTMDand Adogen 140, both hydrogenated tallowalkylamine, were judged to bevery similar, so the Armeen reactions were not filtered. Residue weightsare given in the table 10 below.

TABLE 10 Rx Rx Rx Rx Rx Rx Rx Rx Amine #1 #2 #3 #4 #5 #6 #7 #8 Armeen2HT 0.05 0.18 0 0 0.05 0.02 0 0.56 Armeen 18D 0.43 0.37 0.06 0.15 0.240.12 0.14 0.48 (Note 1) Adogen 101 0.61 0.46 0.05 0.13 0.34 0.08 0.040.91 Adogen 140 0.35 0.85 0.04 0.16 0.17 0.07 0.07 0.97 Average of 0.460.56 0.05 0.15 0.25 0.09 0.08 0.79 Armeen 18D, Adogen 101, and Adogen140 (Note 1-This was the first filtration performed, and inadvertentlyemployed a polycarbonate filter membrane, #which was incompatible withthe THF solvent. The filter membrane was partially dissolved and some ofthe #insoluble material was lost, so the 0.48 g represents the minimumquantity of undissolved solid present in #the original THF mixture.)

By examining the results in the table, it is clear that the amidesprepared from the primary amines Armeen 18D, Adogen 101, and Adogen 140have similar solubility properties while the amides prepared from thesecondary amine Armeen 2HT have significantly higher solubility (lessinsoluble residue). It is possible to prepare amide-esters withsignificant amounts of fluorinated ester groups which still have goodsolubility, particularly using the secondary amine Armeen 2HT (reactions5 and 6). The mole ratio of reaction 3 provided products, which werealmost completely soluble, even in the case of the primary amines. It isalso clear that the diamides have lower solubility (reaction 8 results).

To help visualize and interpret these results, the solubility data wasevaluated using an experimental design software package, ECHIP (ECHIP,Inc., 724 Yorklyn Road, Hockessin, Del., 19707). The model used was aninteraction model, which considers dependence on individual components(e.g. amine content) as well as interactions (e.g. cross terms such asamine×Exxal 13). FIGS. 6 and 7 illustrate the ECHIP model resultsshowing how the amount of insoluble solid varies with on the compositionof the amide-ester. In the figures, end group composition is normalizedto 1.0; for example, the ester amide with equal amounts of Zonyl, Exxal,and amide end groups would lie at the center of the triangle (0.33 molefraction of each end group).

From these triangle plots, several conclusions can be drawn: (1) It ispossible to prepare partially-fluorinated mixed ester amides which havegood solubility in THF, (2) the amount of amine present in thecomposition (resulting in amide ends) has a major effect on solubility,with the least amount of insoluble solid being present at the lowestamide content, (3) compositions in the center region of thethree-component composition space have highest solubility in THF.

Since the mole ratio of reaction 3 provided products which were almostcompletely soluble, even in the case of the primary amines, thisreactant ratio was chosen for scaleup. One example is given below.

EXAMPLE 7

Preparation of Ester Amide from Dodecanedioic Acid, Zonyl BA, TridecylAlcohol, and Di(Hydrogenated Tallowalkyl)Amine:

A mixture of 46.06 g DDDA (0.200 mole), 60.98 g tridecyl alcohol (Exxal13 from Exxon, 0.308 mole), 31.68 g Zonyl BA (0.066 mole), 33.67 gArmeen 2HT (0.066 mole), 10 g Dowex 50W X2-400 strong acid ion exchangeresin (used as esterification-amidation catalyst), and 63.84 gcyclohexane was heated to reflux. The mole ratio of the reactants used,DDDA:Exxal:Zonyl:Armeen was 1.0:1.54:0.33:0.33, is similar to screeningreaction #3 above example 6, except that the amount of Exxal wasincreased to ensure complete reaction and to increase reaction rate.Water was separated from refluxing cyclohexane using a condenser andDean-Stark trap. The reaction temperature was initially about 100-105°C. Water was drained from the trap and cyclohexane was added asnecessary to maintain reaction temperature at or below 118° C. After 25hours total reaction time, the acid number was 58. The reaction wasfiltered to remove the Dowex catalyst. The filtered crude product washeated to 200° C. while sparging with nitrogen, then the pressure wasreduced to 50 torr while continuing the nitrogen sparge. The purpose ofthis stripping procedure was to continue the reaction and to removeexcess, unreacted Exxal 13. The stripping procedure was continued forabout 7 hours, when analysis by gas chromatography showed that residualExxal 13 had been removed. The acid number had decreased to 19.

The product was analyzed by ¹H NMR, which was interpreted as follows. Atriplet at 4.4 ppm was assigned to the O—CH₂— protons of a Zonyl esterend. A group of broad mulitplets between about 3.8 and 4.2 ppm wasassigned to the O—CH₂— protons of Exxal ester ends (many differentstructures because Exxal 13 is a complex mixture). A pair of mulitpletscentered around 3.25 ppm was assigned to the —N—CH₂— protons of an amideend derived from the Armeen 2HT. Integration of these signals suggesteda composition of about 5.2% Zonyl ends, 80.7% Exxal ends, and 14.2%Armeen amide ends (composition normalized to 100%), which suggested afluorine content from the Zonly ends of 4.8% F. Elemental analysisshowed 4.96%F.

This material was tested using the BOCLE procedure described previously.Results are shown in FIG. 8.

Having thus described and exemplified the invention with a certaindegree of particularity, it should be appreciated that the followingclaims are not to be so limited but are to be afforded a scopecommensurate with the wording of each element of the claim andequivalents thereof.

I claim:
 1. A non-symmetric, partially fluorinated compound having amolecular structure: R_(1f)—F′—R₂—F″—R_(3h) wherein R_(1f) represents awholly or partially fluorinated C₁ to C₄₀ organic residue end groupother than a fluoroalkylether group; F′ and F″ represent functionallinkages which are carboxylic esters; R₂ represents the hydrocarbonbackbone selected from the group consisting of a C₇ to C₃₀ alkyl, C₃ toC₃₀ cycloalkyl, an aromatic group, and mixtures thereof; provided whenR₂ is an aromatic group, then the fluorinated compound is difunctional,and R_(3h) represents a non-fluorinated C₁ to C₄₀ organic residue endgroup.